In the present invention heat dissipating device, a plurality of fins 100 are formed. Each fin 100 has a U shape and has an upper folded edge 200 and a lower folded edge 300 (referring to FIG. 1). Each folding edge 200, 300 has an ear 400. A hole 500 is formed at a rear side of the ear 400. The size of the hole 500 is slightly greater than that of the ear 400. In assembly, the ear 400 of one fin 100 is embedded into the hole 500 of another fin 100 so as to combine two fins 100. The heat dissipating device can be installed to a computer central processing unit. However the prior art ear has a simple structure. Thereby the buckling structure is easily released. Furthermore, the thermal expansion and cold contract increases the problem. This induces a trouble to users and increases the cost. It is necessary to be improved.